An interposer is the name for an interface that links one electrical connection to another. In this repair, it is the board connecting the battery to logic board.
Lift the Interposer off the logic board and remove it.
Removing this board will ensure that the battery remains disconnected throughout your repair, preventing your computer from accidentally powering on. It's also a good idea to take it out so it doesn't fall out unexpectedly.
Use the flat end of a spudger to pry the right side of the I/O board data cable connector up off its socket on the I/O board.
When prying the I/O board data cable connector from its socket, make sure to pry the connector itself and not the socket. Prying the socket may cause irreversible damage to the I/O board.